The present invention provides a method for obtaining optically active 3-chloro-2-methyl-1,2-propanediol, the method comprising: a first step of letting at least one kind of microorganism or processed product thereof having an ability to leave untouched (R)-3-chloro-2-methyl-1,2-propanediol or (S)-3-chloro-2-methyl-1,2-propanediol in the presence of an enantiomeric 3-chloro-2-methyl-1,2-propanediol mixture act on an enantiomeric 3-chloro-2-methyl-1,2-propanediol mixture; and a second step of recovering the untouched optically active 3-chloro-2-methyl-1,2-propanediol.